I'm trying to make a simple setup for running a stepper motor at very low speed. For some reason I keep burning the A4988 drivers. The motor is 1.5 A, and I have adjusted the A4988. If I use a 9V battery as the power source, everything works fine. When I switch to a power supply set to the same 9V, I instantly burn the driver. Does anyone know why this happens?
I guess nobody will know without your schematic and, perhaps, a code
2 Likes
Would that be a PP3 battery by any chance ?
If so, then it is not capable of delivering a large amount of current and hence may not cause the problem
The A4988 driver is only good for 1A unless it has a good heat sink and active (fan) cooling.
How did you adjust the driver? What value did you use for Vref? What is the value of the sense resistor on your A4988 module?
Is this your 9V battery?
I second the request for a schematic and your test code.
Read the forum guidelines to see how to properly post code and some good information on making a good post.
Use the IDE autoformat tool (ctrl-t or Tools, Auto format) before posting code in code tags.
You need to set the current limit on the A4988 to 1 Ampere or less. If you have a genuine Pololu A4988 board, follow their instructional video.
If not, you will have to determine what value of current sense resistor the manufacturer used, and follow the instructions in the A4988 data sheet.
Sorry for the lousy first post, and thank you for your answers anyway.
I think my problem was the A4988 boards. They were some cheap no brand ones.
I did set the reference voltage as described all over the internet, and they fried in seconds delivering less than 1A.
I purchased another batch of A4988 boards, and everything works as it should.
Hi If you do not have an 'intelligent' stepper controller board, you can only use a voltage supply that is exactly required by the motor rating figure.
When using an advanced type of controller, the voltage supply is typically very much higher value in order for the motor to maintain the exact rated current across the RPM range(You can search more on different sites) , as inductive reactance increases with rpm. You can seach further on youtube or google
This is a feature of the advanced controller types.
BatliaBano
1 Like
This topic was automatically closed 180 days after the last reply. New replies are no longer allowed.